[PATCH v2] vmap(): don't allow invalid pages

[Andrew Morton]

On Tue, 18 Jan 2022 17:21:09 -0800 Yury Norov <yury.norov at gmail.com> wrote:

> vmap() takes struct page *pages as one of arguments, and user may provide
> an invalid pointer which would lead to data abort at address translation
> later.

Does "user" mean userspace code?

If so, please tell us much more about the means by which userspace can
trigger this problem.